1. Field of the Invention
This invention relates to a roller for guiding knitwear produced on a knitting machine, with at least one stub shaft of reduced cross-section projecting to the side of a middle part and at least one first adjusting ring which can be fixed on one of the stub shafts to form annular gap and which has a first axial end with an outer diameter corresponding to the outer diameter of the middle part and a second axial end associated with the annular gap. The invention also relates to a device comprising such a roller.
2. Description of the Prior Art
Tubular or circular knitted knitwear is as a rule taken down from the loop forming region of the knitting machine by a take-down device having two or more take-down rollers, regardless of whether is it produced on a flat or a circular knitting machine. The take-down rollers form nips therebetween, into which the tubular kit or knitted hose is passed, laid flat and folded at its longitudinal edges. The knitwear is also pressed at its longitudinal edges by the nip action and is creased. The creased edges resulting from this load to persisting changes in the knitwear or in the yarns, especially with the production of fabrics plated with elastic threads or when using synthetic fibres, and cannot be removed, or can only be removed with difficulty, by subsequent treatment of finishing of the knitwear.
It is therefore already known to avoid the occurrence of such pressure creases in that the knitwear is cut in the longitudinal direction before passing through the take-down rollers and is then spread out flat and then wound up in a single layer (DE 691 21 291 T2). Compared with the normal technique a double width take-down device is therefore required, which is expensive and undesirable for reasons of space. Moreover a greater space from the loop forming region has to be kept for the spreading out flat and winding up in a single layer, since the stitch rows which are normally straight and parallel to one another otherwise suffer strong wavy distortion, so that in addition to the wide construction of the machine there is also a higher construction, or else distorted stitch rows are obtained. In on the other hand the knitwear is cut in the longitudinal direction at two diametrically opposite places, which is also known (DE 39 37 990 C2), and the two layers thereby obtained are wound up with separate winding rollers, not only is a second winding roller necessary, with an increased cost of construction, but only half width fabric is obtained compared with the conventional technique.
In order to avoid such structural changes, take-down rollers are known (DE-GM 1 680 242) which are provided with reduction in diameter at a fixed axial position, forming an annular gap at each of its ends, where the creased edges normally come to lie. Since the hose width of knitting can vary, depending on the selected knitting construction, the yarn and other influential values, a special take-down roller has to be made for each fabric with and mounted in bearings, which is expensive and can result in frequent stoppages of the knitting machine. It is therefore also already known (DE-PS 1 585 042, DE-GM 1 860 242, GB-PS 1 118 547) to make the position of this annual gap variable in the axial direction of the take-down roller, in order to make it possible for the side edges to lie always with only a short section in the annular gap. The production of the annular gap and the adjustment of its position are effected as a rule with the aid of adjusting rings, which can be fitted against the end faces of a middle part of the take-down roller, or removed therefrom, their outer diameter corresponding to that of the middle part and it being possible to do this in part without dismantling the take-down roller. However the known constructions have the disadvantage that the adjusting rings have to have comparatively sharp edges at their side edges, formed by 90.degree. corners, so that in all conceivable settings, on one side they continue flush with the outer periphery of the middle part of the take-down roller or an adjusting ring lying against this, while on the other side they either adjoin an annular gap or continue flush into the outer periphery of a further adjusting ring. These sharp edges bear at least in part on the knitwear as it is taken down and then often lead to impressions and/or indentations therein, which can involve remanent changes which cannot be obviated by further treatment, or only with difficulty.
Corresponding problems can result in guiding knitwear of the kind described with other rollers, e.g. in guiding by means of a winding roller or in the gap between a winding roller and a drive roller associated therewith.